Sharding Techniques in the Era of Blockchain

Abstract

Blockchain is a peer-to-peer ledger that records a growing list of transactions in a tamper-resistant manner using cryptographic hashes. Centralized points of vulnerability are eliminated in blockchain, and so it is considered secure by design under some reasonable assumptions, such as honest majority. But scalability remains a major limitation that can be improved by sharding. Full sharding is one of the approaches in achieving the high performance of blockchain systems. This paper proposes a locality-based full sharding protocol in permissioned blockchains. We introduce a simple and efficient cross-shard transaction handling protocol. A prototype is under development based on Hyperledger Fabric.